David Cameron knew how to arrive, and how to leave. There wasn’t too much of that awkward standing about on the platform, when everything has been said and the train won’t go.

“I was the future once,” he remarked, winding things up by using against himself the jibe he flung at Tony Blair when first confronting him across the Dispatch Box.

The Tory benches rose as one and clapped. Sir Nicholas Soames, and other Tories who had decided on this most crowded of days to sit in the gallery, rose and clapped too.

The Labour Party, with very few exceptions, did not rise and clap. Some will see this as ungracious – indeed it was ungracious – but perhaps it also showed, unintentionally, how that party is receding into the past, when clapping was not at all the done thing in the Chamber.

And Cameron has not made life easy for them. By continuing since 2010 to run an enormous deficit, the Tory-dominated Government made it impossible for Labour to promise with credibility to run an even larger one.

Cameron remarked today that in the time it has taken the Tories to get rid of one leader and choose another, Labour “haven’t even decided what the rules are yet”.

Jeremy Corbyn made one admirably graceful remark, sending his thanks via Cameron to the Prime Minister’s mother “for her advice about ties and suits and socks”.

But the day belonged to Cameron, whose wife and children were watching from the public gallery, behind the glass screen installed in a fit of panic after a protester with a good aim managed to hit the then Prime Minister, Blair, on the shoulder with a flour-filled condom.

Theresa May was greeted, as she entered the Chamber six minutes before PMQs, with a tremendously solid cheer from the Tory benches. The tribe has united behind her, after slaying various other contenders.

A minute later, David Cameron was greeted with an even louder cheer as he took his place, flushed and smiling, on the front bench, and waited for Welsh Questions to draw to a close.

Boris Johnson stood at the far end of the House for a minute or two, contriving to look perfectly cheerful, before retiring to an inconspicuous seat. He was the future once, and may be again, but this half hour belonged to Cameron, and May now stretches before us.